The rapid increase in vehicle traffic on the roads and the associated queues and travel time extensions are resulting in increased efforts worldwide to identify traffic states and take them into account for the route selection or for route calculation in navigation systems. It is also possible to take account of these traffic states in driver assistance systems.
Digital maps, which are used for navigation systems and driver assistance systems, are usually already outdated when they are delivered. For this reason, an update for the map is indispensable if the digital map is intended to correspond to the current circumstances. Such an update is usually provided by selling storage media on which the update data are stored.
What is known as a traffic message channel (TMC) can be used to send coded traffic messages, inaudibly, at the same time as the radio programs. However, TMC can only ever be used to cover a limited area, since the range of radio signals is limited.